Background
Observations
 

Meteorites from the Moon are the most coveted of all including those from Mars. Although Martian meteorites are rare, Lunaites are many times rarer by weight. Several Martian meteorites have been observed as falls but not a single one from the Moon has ever been witnessed. Lunar meteorites are so scarce that none have been found on the North or South American continents!

"Meteorites from the Moon are the most coveted of all including those from Mars."

If you took all of the official lunar meteorites and weighed them as of the time this was written, you would come up with a scant 43,420 grams. Take out 4,708 grams for the Antarctic finds which are protected under international treaty. Then remove the unavailable Kalahari stones which unofficially weighed 14,098 grams and a figure of 24,614 grams is left. Furthermore, when the estimated 11,200 grams that are locked down in museums and large collections are taken into account, a mere 13,414 grams is left and this figure does not include type specimen repositories and cutting loss amounts (totaling around 26%). What all this means is that normally less than a few kilograms of lunar material will ever be available at any given time. By comparison, there are several metric tons of diamonds on the market!

 
  Earth as seen from the lunar surface of the moon